LIPID DISTRIBUTION ON TEXTILES RELATIVE TO WASHING WITH LIPASES

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
804	5199	1103	100%

Progress 10/01/97 to 09/30/07

Outputs
OUTPUTS: Research was conducted on a number of detergency issues including splitable or reversible surfactants that will reduce the organic load on waste treatment facilities from industrial cleaning. This work suported further development of specialty products in the chemical industry. With the support from a major consumer product company, difficult laundry soils were studied. This fundamental understanding of the aging of soils on textiles was used by the soap and detergent industry for improved product development. Enzymes are used in laundry detergents to enhance cleaning. Research was conducted in collaboration with a major producer of industrial enzymes to study the use of a new genetically engineered lipase, as well a cellulase. Fabric care products such as laundry detergents and fabric softeners are used to deliver aroma chemicals onto textiles to enhance fragrance. A collaborative research project was conducted with a large company that produces fragrances to understand the basic science of deposition and adsorption of aroma chemicals on textile fibers. This research was disseminated directly to major industry involved in product development for fabric care. Basic understanding was gained and disseminated through scientific and technical literture for the industries involved in fabric care and textiles. PARTICIPANTS: Over the time of this project, three graduate students received Ph.D.s from research that was part of this project: Eun Kyung Choe, Yeong Seung Chi, Vasudha Ravichandran. Another student received a MS degree: Arindam Varanasi. A fourth PhD student, Jooyun Kim, conducted research on this project. Two undergraduate students, W. Y. Fok and L. Petrick, worked on this research and are co-authors/first authors on published research papers. One postdoctoral associate, Haiqing Liu, and one research support specialist, M. Laduca worked on this research. Six visiting professors worked on this project from time-to-time: C. Ahn, K-H. Song,D.N. Hild, J. Borsa, I. Racz, J-S. Lee., G. Bodor. Scientists from major companies participated in the research and some in publication of the research: R. Kuniz, M.J. Leonard, J.J. Young, M.J. Incorvia, M. Hockauf, M. Thellerson, V. Skovgaard Nielsen, T. Sejersgard Fano, L.S. Pedersen, R. Mejldal, A.F. Joseph, D. Galante, B. Stefl. TARGET AUDIENCES: The major audience for this research is the technical personnel that produce ingredients or formulations of fabric care products. Their products address hyigene and health of consumers and the public. Some make industrial products, some produce components for soaps and detergents industries, and others produce consumer products. Technical personnel in the fiber and textiles industries are also audiences for this research.

Impacts
Fundamental research was conducted to understand a number of basic phenomenon important to fabric care and detergency. This research impacted the research and product development in the supporting industries worldwide. The research reported in the terminal year addressed the formation of malodor on active sportwear due to bacterial enzymes on sweat and body soil. Bacterial action on apocrine sweat results in the formation of malodor compounds including free steroids, acids, and aldehydes. Among these compounds is 5alpha-androst-2-en-17-one (A-17 one) formed by axillary bacteria from androsterone sulfate present in apocrine secretion. Based on a review of literature, a laboratory method was developed to evaluate the effectiveness of antimicrobial treatments for textiles in the reduction of malodor on garments used for active sportswear. Androsterone sulfate was used as the odor precursor with Corynebacterium striatum to yield A-17 one as a metabolite. A GC-MS method of separation and quantification of A-17 one was developed and applied to fabrics made from poly (ethylene terephthalate) (PET) fibers that contained 0.5 or 1.0 % silver zirconium phosphate as an antimicrobial agent. The antimicrobial agent significantly reduced the production of the malodor compound. Higher amounts of A-17 one were observed on fabrics contaminated with sebum, illustrating the role of residual body soil on the formation of malodor by bacterial action. We conclude that this method can be used to study the formation of malodor on textiles that is due to action of skin bacteria on apocrine sweat and sebum without the requirements of sterile incubation conditions.

Publications

Obendorf, S.K., Kim, J. and Kuniz, R. 2007. Measurement of Odor Development Due to Bacterial Action on Antimicrobial Polyester Fabrics, AATCC Review, 7(7):35-40.
Ahn, C. and Obendorf, S.K. 2007. GC-MS Analysis of Curcumin Dye after Selective Degradation Treatment, Fibers and Polymers, 8(3), 278-283.
Song, K-H. and Obendorf,S.K. 2006. Chemical and Biological Retting of Kenaf Fibers, Textile Research Journal, 76:751-755.

Progress 01/01/06 to 12/31/06

Outputs
Electron microscopy, backscattered electron imaging, and X-ray microanalyses were proposed to study the deposition and distribution of fabric softeners on textile structures during the laundry processes. The methodology was based upon previous studies that evaluated the distribution of fatty material and other organic substances such as aroma chemicals on textiles using chemical tagging and electron microscopy. A protocol was developed for analysis of quartenary fabric softener on cotton fibers surfaces was developed. It will be applied to cotton fibers from terry cloth fabric that has been washed with three detergent systems with differing pH for multiple cycles with rinse applied fabric softener. Spin finishes, including lubricants, emulsifiers, antistatic agents, and wetting agents are used to facilitate the manufacturing and processing of textiles. Autoxidation of ten spin finish components was studied by subjecting them to air and heat over time. Chemical changes were observed visually and evaluated using UV/Vis spectroscopy, viscosity measurements, and FTIR. Yellowing occurred for HCO-16, TMP, wetting agent, coconut oil ethoxylate, and coconut oil. Changes in solubility were observed for wetting agent. Significant changes in viscosity were measured for CO-16, HCO-25, anti-static agent, and wetting agent. Finally, changes in FTIR spectral ratios were observed for CO-25, HCO-16, CO-16, and anti-static agent. Chemical changes observed were consistent with autoxidation of spin finish components. Soiling of nylon 6, 6 carpets was studied to investigate the effect of spin finishes with and without fluorocarbons finishes; as well, use of a secondary extraction process examined to determine the effect of removing residual spin finish oils. Two types of residential carpet of intimate blend trilobal fibers with two modification ratios were evaluated: one had fluorcarbons in the spin finish with an additional topical mill-applied fluorocarbon. The second carpet had no fluorocarbons in the spin finish, but had a topical mill-applied fluorocarbon finish so that both carpets had a target of 250 to 300 ppm fluorine. Acetone extraction was used to remove the spin finishes from the carpets. Both carpets with and without extraction were soiled with particulate soil in the laboratory. Visual ratings and color difference measurements indicated more soiling on the carpets that had been extracted. Fluorine analysis showed that fluorcarbons were removed from both carpet types with the acetone extraction. Electron microscopy indicated the deposition of soil in the V-groove of the filaments with the higher modification ratio. As well, fiber surfaces near the face of the carpet exhibited higher levels of soil than surfaces located near the carpet backing.

Impacts
Basic understanding of the distribution of spin finishes on nylon carpet fibers was developed. The oxidation of this finishes during use was defines, as well as the role of the spin finishes on carpet soiling during use.

Publications

Fok, W.Y., Hild, D.N. and Obendorf, S.K. 2006. Autoxidation of Spin Finishes. Textile Research Journal, 76:614-618.
Ahn C. and Obendorf S.K. 2006. GC-MS analysis of dyes extracted from turmeric. Fibers and Polymers, 7(2):158-163.
Petrick, L.M., Hild, D.N. and Obendorf, S.K. 2006. Observations of Soiling of Nylon 66 Carpet Fibers. Textile Research Journal, 76:253-260.
Obendorf, S.K., Liu, H., Young, J. and Incorvia, M.J. 2006. Effect of Vapor Pressure of Aroma Chemicals on Their Retention on Cotton and Polyester Fabrics. Journal of Applied Polymer Science, 99:1720-1723.
Ahn, C. and Obendorf, S.K. 2005. Analysis of Degradation Products in Madder Dyed Fabrics in Selective Degradation Conditions. Journal of the Korean Society of Clothing and Textiles, 29: 1608-1618.

Progress 01/01/05 to 12/31/05

Outputs
The role of electrolytes in the aroma chemical adsorption on fabric was assessed. Existence of electrolyte in aqueous solution not only dramatically decreases the CMC of surfactant, but it changes the electrical potential of fiber surface through adsorbing counter ions on the fiber surface. Monovalent electrolyte NaCl at two concentrations, 10 mM and 100 mM, was used to investigate aroma chemicals adsorption on cotton. In addition, we further probed the effect of aroma chemical structure on adsorption on cotton from two aqueous surfactant systems (CTAC and SDS). Eleven aroma chemicals were tested including four types of chemicals, i.e., ester, aldehyde, ketone, and alkanol. Each type consists of 2 or 3 aroma chemicals with saturated, unsaturated, conjugated, cyclo, bicyclo or tricyclo structures. Adsorption was enhanced by surfactants with cationic CTAC resulting in more adsorption than anionic SDS. Adsorption is attributed to solution physical entrapment, hydrophobic interaction, dispersion forces, and interaction with surfactant molecules adsorbed on fiber. Log P, as well as apolar surface area, and water solubility are important factors in adsorption of aroma chemicals, and they are interactive. Water solubility increases the attainable concentration of the treating solution thus increasing that which is retained in the textile capillaries. Hydrophobicity increases the selective portioning of the aroma chemical onto the fiber surface particularly in the presence of surfactants. There was some evidence of polar-polar interaction between aroma chemical and cellulose. In no surfactant solution, more adsorption is often observed in systems with 100 mM NaCl than 10 mM NaCl. The screening effect of electrolyte increases with the electrolyte concentration. Thus, the energy of the liquid-solid interface is reduced. This lower interfacial energy results in increased adsorption and spreading of the aroma chemical on the fiber surfaces. Screening effect of electrolyte affects aroma chemical adsorption most for anionic surfactant system. Increase in the concentration of the electrolyte, increases the screening effect that reduces the repulsive forces between the anionic surfactant molecules and the weakly electronegative cotton fiber surfaces. In a cationic surfactant system, the screening effect of the electrolyte reduces adsorption of aroma chemicals with increased electrolyte concentration. This is due to the screening reducing the attraction between cationic surfactant molecules and the weakly electronegative cotton fiber surface. Functionality shows significant effect (alkanol-ketone-aldehyde-ester). Aroma chemical adsorption increased with increase in ovality of the aroma chemical molecule for compounds with higher adsorption on cotton. While conclusions are limited by the small number of aroma chemicals analyzed, there is evidence that molecular shape within a chemical class of compounds influences significantly the adsorption of the aroma chemical on cotton.

Impacts
Basic mechanistic information obtained can be used to improve the performance of consumer products used for fabric care.

Publications

Obendorf, S.K., Liu, H., Leonard, M.J., Young, T.J., Incorvia, M.J. 2006. Effect of Vapor Pressure of Aroma Chemicals on Their Retention on Cotton and Polyester Fabrics, Journal of Applied Polymer Science, 99:1720-1723.
Liu, H., Obendorf, S.K., Leonard, M.J., Young, T.J., Incorvia, M.J. 2005. Distribution of aroma chemicals on textile fibers, Perfumer & Flavorist, Vol. 30, March/April 2005, p. 54-60.
Liu, H., Obendorf, S.K., Leonard, M.J., Young, T.J., Incorvia, M.J. 2005. Adsorption of Aroma Chemicals on Cotton Fabric from Aqueous Systems, Journal of Surfactants and Detergents, 8:311-318.

Progress 01/01/04 to 12/31/04

Outputs
Aroma chemical adsorption on cotton fabric from an aqueous system is affected by surfactant system, surfactant concentration, hydrophilic-hydrophobic nature, and fiber morphology. Higher aroma chemical adsorption was observed with surfactant than without. Aroma chemical adsorption increases, achieves a maximum, and then decreases with increasing surfactant concentration. Aroma chemical absorption by textiles proceeds by both physical and chemical processes. Physical entrapment of aqueous media results in higher retention of aroma chemical with increased water solubility. Chemically, aroma chemicals that are more hydrophobic are partitioned from the aqueous phase onto cotton fabric. The higher concentration of the solution held on fabric - for rosalva compared to carvone indicates the influence of molecular interactions such as hydrogen bonding in adsorption on cotton. Aqueous surface tension also influences aroma chemical adsorption; the lower the aqueous surface tension the greater the adsorption. This can be related to greater wicking of the media into the textile structure. Fiber morphology impacts aroma chemical adsorption; mercerized cotton fabric, which has a higher pore volume and more accessible internal surface area, adsorbs more aroma chemical than untreated cotton fabric. The influence of capillary and pore structure on adsorption illustrates the influence of physical retention on adsorption of aroma chemicals from liquid media.

Impacts
This research provides basic mechanistic information that is being used to improve the performance of consumer products used for fabric care.

Publications

Obendorf, S.K. 2004. Microscopy to Define Soil, Fabric and Detergent Formulation Characteristics that Affect Detergency: A Review, AATCC Review 4 (1):17-23.
Liu, Haiquing, S. Kay Obendorf, Timothy J. Young, Michael J. Incorvia. 2004. Microscopic Analysis of Aroma Chemical Distribution on Fibers, Journal of Applied Polymer Science, 91:187-192.
Obendorf, S.K. Haiqing Liu, Michael J. Leonard, Timothy J. Young, Michael J. Incorvia. 2004. Fragrances on Fibers, Household and Personal Care, Supplement to Chimica Oggi, Chemistry Today, pp. 51-54.

Progress 01/01/03 to 12/31/03

Outputs
Adsorption of aroma chemical molecules from an aqueous surfactant system was studied on cotton fabric. In the laundry process, surfactant is used to remove organic and inorganic soils, while aroma chemicals are required to transfer from the same system to the fabric to be released in the subsequent drying, storing, and use. A systematical study was performed on the following factors: surfactant type, surfactant concentration, fiber morphology, and concentration of aroma chemical in water. Anionic surfactant sodium dodecyl sulfate (SDS) enhanced the adsorption of aroma chemicals on cotton fabric at concentrations below c.m.c. When the SDS concentration is above c.m.c., the aroma chemical molecules dissolve in SDS micelles lowering the concentration of free aroma chemical molecules in solution, resulting in lower adsorption of aroma chemical. At concentrations above and below c.m.c., cationic surfactants, cetyltrimethylammonium chloride (CTAC) and cetylpyridinum chloride monohydrate (CPC), enhanced the adsorption of aroma chemical on cotton fabric. In most cases mercerized cotton fabric adsorbed more aroma chemicals than untreated cotton; this is related to changes in fiber morphology due to the finishing process that increase pore volume and accessibility to the internal surfaces.

Impacts
This research provides basic mechanistic information that is being used to improve the performance of consumer products used for fabric care.

Publications

Obendorf, S. Kay, Arindam Varanasi, Rie Mejldal and Vibeke Skovgaard Nielsen. 2003. Lipid Distribution on Cotton Textiles in Relation to Washing with Cellulase, Journal of Surfactants and Detergents 6:1-5.

Progress 01/01/02 to 12/31/02

Outputs
Fragrances have been widely used in soaps, detergents, household goods and food industry. Besides the odor characteristics, other performances criteria like odor threshold, substantivity, toxicity, transparency, stability, and biodegradability are also important parameters of odorants. Among those parameters, substantivity, which is defined as the behavior of fragrance in the application on fabrics, e.g. the distribution and residuality of a perfume in its use in a laundry-washing process, is a primary concern in the deposition and retention of fragrance on fabrics. Basic studies of the mechanisms for the deposition of aroma chemicals onto fibers were undertaken. GC/MS analyses were used to measure the total amount of these aroma chemicals that are deposited on select textiles. Backscattered electron images in the scanning electron microscope along with x-ray microanalyses were used to study the deposition of these fragrances on and within the fiber structure. Aroma compounds that are known to vary in substantivity to textile fibers were evaluated. In addition the fibers/fabrics were varied to further understand the mechanisms of deposition, adsorption, and retention of these classes of chemicals on various textile substrates. To better understand substantivity, time-dependence of fragrance retention on fabric with varied physical and chemical characteristics (cotton, lyocell, polyester) were studied. Based on these data, we evaluated two interrelating factors, i.e., molecular structure of fragrance and chemical structure and physical morphology of fabric, on the deposition and retention of fragrance, in order to elucidate the mechanism. Unsaturated aroma compounds cis-3-hexenyl salicylate and linalyl acetate were applied to 100 percent cotton, lyocell or polyester fabrics from an alcohol solution by pipette. Osmium tertroxide was reacted with the unsaturated aroma chemicals providing a tag in the backscattered electron imaging and x-ray analysis. Fragrances mainly deposit and distribute over the entire fiber surface, with higher concentrations in surface irregularities and morphological structures such as the crenulation in cotton. Low amounts of fragrance are deposited on internal surfaces within the cotton fibers. The physical and chemical nature of fiber plays an important role in the retention and distribution of fragrance. The defects, tiny fibril and irregular locations retain higher concentrations of fragrance. The capillary structure formed by close packing of fiber such as observed for lyocell and PET fibers accumulated high concentrations of fragrance. Vapor pressure of fragrances has the expected effect on the retention of fragrance on the fibers, and this effect is graphically presented in the microscopy. Low vapor pressure of the fragrance increased retention of the fragrances on the fiber surfaces.

Impacts
Basic knowledge on distribution of fragrances on fibers provide mechanistic understanding of the phenomena and performance of aroma chemicals that can be used by industry to develop new and innovative personal and fabric care products.

Publications

Obendorf, S. K., Hockauf, M. and Thellerson, M. 2002. Lipid Distribution after Washing with Lipases: Microscopy Analysis, Pharmachem, July and August, pp 51-54.
Obendorf, S.K. 2002. Microscopy to Define Soil, Fabric and Detergent Formulation Characteristics that Affect Detergency, AATCC International Conference & Exhibition Proceedings, Charlotte, NC, October 1-4, 2002, p 277-285.
Obendorf,S.K., Skovgaard Nielsen, V. and Sejersgard Fano, T. 2002. Lipase and Cellulase Enzymes in Laundry Detergents: Microscopy Analysis, CHIMICAoggi/CHEMISTRY Today, Volume 20, No. 9, p. 40-43.
Obendorf, S.K., Mejldal, R., Varanasi, A. and Thellerson, M. 2001. Kinetic Study of Lipid Distribution after Washing with Lipases: Microscopy Analysis, Journal of Surfactants and Detergents, 4:43-55.

Progress 01/01/01 to 12/31/01

Outputs
Enzymes are used widely as effective additives to laundry detergents for improved detergency on soiled fabric. They have potential for cleaning of "dingy" soils in addition to the stain removal benefits. Cellulases contribute to the overall whiteness of cotton containing textile when worn and washed several times, meaning that their cleaning is not associated solely with the regions characterized by high amounts of fatty material, e.g. collars/cuffs. The focus of this research was to further study the performance of cellulases for whiteness maintenance of cotton textiles. Cotton garments soiled by multiple wearing and washed using a cellulase treatment were evaluated using electron microscopy and X-ray microanalysis. Washing with cellulase significantly reduced residual soil concentrations at all morphological locations on the cotton fibers for each set of matched garments. The relative concentrations of residual soil on the fabrics agreed well with the color differences measured at 440 nm. Cellulase affected removal of oily soil from within the cotton fiber secondary wall resulting in residual oil concentration similar to morphological locations that were more accessible for detergency such as the fiber surface and crenulations. Since cellulase hydrolyzes cellulose, it was expected that the effect would be within the structure of the fiber, i.e. secondary wall. The cellulase effect was similar on redeposition garments as on garments worn and washed. Like with lipase, the enhanced removal of soil from the interior bulk structure of the cotton fiber with use of cellulase is unique, since most other detergent components have higher functionality at fabric, yarn, and fiber surfaces. We think that cellulase is functioning by hydrolyzing cellulose from the internal surfaces of fibrils within the secondary wall opening up the pore structure for enhanced detergency and forming a new surface with each washing.

Impacts
The performance of newly genetically engineered enzymes for use in laundry detergents have been characterized to enhance the basic understanding of the mechanistic action of these fabric care components on cotton textiles. This enables the industry to develop new and innovative fabric care products.

Publications

Varanasi, A., Obendorf, S.K., Pedersen, L.S., and Mejldal, R. 2001. Lipid Distribution of Textiles in Relation to Washing with Lipases, Journal of Surfactants and Detergents, 4:135-146
Obendorf, S.K., A. Varanasi, R. Mejldal, and M. Thellersen. 2001. Function of Lipase in Lipid Soil Removal as Studied Using Fabrics with Different Chemical Accessibility, Journal of Surfactants and Detergents, 4:233-245.
Obendorf, S.K. and Borsa, J. 2001. Lipid Soil Removal from Cotton Fabric after Mercerization and Carboxymethylation Finishing, Journal of Surfactants and Detergents 4:247-256

Progress 01/01/00 to 12/31/00

Outputs
Effect of lipase on removal of lard from a cotton fabric by detergency was studied in detail by radioisotope and X-ray microanalysis over 60-min washing. Osmium tetroxide was used to label the soil for microscopy. Backscattered electron images were used to study residual soil present on and within the cotton fibers and in the interfiber spaces of the yarn bundle. Lard soiled samples had large deposits on the fabric surfaces; oil was present in the crenulation, secondary walls and the lumen of the fibers. Relative concentrations of oil were determined for selected morphological locations within the fiber structure and at the fiber surface using X-ray microanalysis. Specimens soiled with lard and tagged with osmium tetroxide immediately from the wash bath at 0, 5, 10, 20, and 60 min provide snapshots of the washing process. Within the yarn structure, domains with high oil concentration developed during washing. These domains were not adsorbed onto the fiber surfaces, but were contained within the twisted yarn structure. The inclusion of lipase "accelerates" the washing process with the dislodgment of the soil from the fiber surface being more complete for the yarn specimens washed with lipase for 20 and 60 min. The three main stages of the soil removal process - transport of water and detergent to the soil on the substrate, separation of soil and substrate, and transport of dislodged soil into the wash bath - were observed. Lipase functions in detergency by hydrolysis of triglycerides forming mono- and diglycerides and fatty acids that are more soluble in water, can undergo soap formation, enhance mesomorphic phase formation, and increase emulsification. The quantification of the mass of the residual oil is well defined using the radioisotope methodology. The effectiveness of lipase on removal of lard stains is observed at all points in the washing cycle (5, 10, 20, 60 min). Our data fit a classical kinetic description of the soil removal process described by an exponential decay, with the presence of lipase greatly increasing the rate of oil removal during the early period of washing (0 to 20 min). With the use of lipase in the washing bath, the amount of soil removal after 10 min is about the same as observed after washing 60 min with detergent only. Washing removes soil located on the fibers and yarns on the fabric surfaces early in the process and more completely. Soil that is located within the yarn structure is removed by washing but this required more time, and lard removal from these interfiber capillaries is greatly enhanced by use of lipase. Washing does remove soil from within the cotton fiber, i.e. secondary wall and lumen, and this is also more complete with the use of lipase. After washing with a detergent for 60 min, the highest concentration of residual soil is in the lumen, although the concentration has been reduced by a factor of two. It appears that the lumen is the last region of the cotton fabric structure to be cleaned by laundering. The use of lipase in the wash bath increased the rate of soil removal for all locations with the cotton fabric and fiber structures.

Impacts
The performance of a newly genetically engineered lipase has been defined as a detergent additive. The kinetics and function of this new lipase has been defined in detail and from a mechanistic perspective. This enables the soap and detergent industry to develop new and innovative products with enhanced product performance to meet consumer needs and to enhance personal and household hygiene.

Publications

Obendorf, SK, Detergency of Used Motor Oil from Textiles, CHIMICAoggi/CHEMISTRYtoday, Teknoscienze, Milan, Italy, (November/December edition, 2000).
Obendorf, S.K., Varanasi, A., Mejldal, R., Study of the Lipid Distribution on Textiles in Relation to Washing with Lipases: Effect of Lipase on Fabric with Different Chemical Accessibility, 91st AOCS Annual Meeting & Epo Abstracts, INFORM 11:S19 (2000).
Borsa, J, I. Racz, S. K. Obendorf, G. Bodor, Slight Carboxymethylation of Cellulose, Proceedings Advances in Wood Chemistry, International Symposium Honoring J. S. Gratzl, Univ Agric Sci, Universitit of Bodenkultur, Vienna, Austria, 1999, P-5.

Progress 01/01/99 to 12/31/99

Outputs
Lipases are used widely as an additive to laundry detergents for obtaining improved detergency on fabric soiled with fatty material. The soil removal of fatty stains from cotton and the efficiency of the lipase during the time of the washing have been evaluated to determine the distribution of lipid in cotton fibers with respect to washing with lipase. In this phase of the research, fabrics of cotton fibers with varied morphology/ chemical accessibility were investigated in order to study the soil accessibility of the detergent and lipase in textiles with different properties. Three cotton fabrics (untreated, mercerized, and carboxymethylated cotton) differing in chemical accessibility were subjected to three treatments - unwashed, washed with detergent, and washed with detergent plus lipase. In addition Tencel lyocell fabric, microdenier manufactured cellulosic fiber, was compared to the cotton fabrics to further understand the effects of fiber morphology on lipase effectiveness, since these two cellulosic fibers have very different morphological fiber structures. Both detergents and lipase remove more soil from the more chemically accessible and hydrophilic textiles, e.g. slightly carboxylated cotton. Lipase increases lipid removal for all fabrics and all morphological locations on the fiber. Use of lipase results in extensive cleaning of the fiber surfaces and interfiber capillaries, with high effectiveness for small capillaries and the center of the yarn bundle. Lipase removes significant soil from the lumen in the untreated and mercerized cottons, the fabrics showing the largest total increases in amount of lipid removed by lipase. When the fiber surfaces were smoother and the fiber structure less open and not carboxymethylated, i.e. the mercerized cotton fabric, more lipase benefit was observed (72 % of the residual soil left after washing with detergent was removed when lipase was added). The total soil removal from the mercerized cotton fabric with use of lipase was equal to that observed for the more open, hydrophilic carboxymethylated fabric and for the Tencel that has no lumen or other morphological features of natural cotton such as crenulations. Lipase appears to enhance lipid removal under conditions where removal by the detergent surfactant system is limited. For example, large lipase benefits have been observed when the washing temperature is below or near the melting temperature of the oil, i.e. lard versus olive oil washed at 30 C. In this case, the detergent roll up mechanism is limited. Increased lipase benefits are observed in cleaning small capillaries such as the crenulations of cotton and the interior capillaries of the yarn bundle, i.e. the center capillaries of the yarn. As well, the lipase benefits were larger for the fiber structures with lower chemical accessibilites, in that the highest amount of additional soil removal with addition of lipase was observed for the mercerized and untreated cotton.

Impacts
This research gives fundamental understanding of the function of lipases in detergency. This information is being used to develop new detergent ingredients through biotechnology. These enzymes are used by companies who formulate detergent products worldwide.

Publications

Obendorf, S. K.,Varanasi, A., Mejldal, R., Pedersen, L. S., Study of Lipid Distribution on Textiles in Relation to Washing with Lipases, Proceedings of the 39th International Detergency Conference, WfK-Cleaning Technology Research Institute, Krefeld, Germany, (1999) pp. 99-123.
Obendorf, S. K., Varanasi, A., Pedersen, L.S., Mejldal, R., Study of Lipid distribution on Textiles in Relation to Washing with Lipases, Division of Surfactants and Detergency, Journal of Surfactants and Detergents 2:443 (1999).
Arindam Varanasi, Study of Lipid Distribution on Textiles in Relation to Washing with Lipase, MS Thesis, Cornell University, Ithaca, NY, January, 2000.

Progress 01/01/98 to 12/31/98

Outputs
The effect of lipase on removal of lard from cotton fabric was studied by radioisotope and x-ray microanalysis methods to study the soil removal process in detail. The backscattered electron images and x-ray microanalysis data from the specimens tagged with osmium tetroxide immediately from the wash bath at 0, 5, 10, 20, and 60 min provide snapshots of the washing process. We observed the development of domains with high oil concentration within the yarn structure during washing. These domains appear not to be adsorbed onto the fiber surfaces, but they seem contained within the twisted yarn structure (the inter-fiber capillaries). The development of these domains is quite apparent in the specimen washed 20 or 60 min with detergent plus lipase. It appears that the inclusion of lipase "accelerates" the washing process with the dislodgment of the soil from the fiber surface being more complete for the yarn specimens washed with lipase for 20 and 60 min. Soil removal involves three main stages: transport of water and detergent to the soil on the substrate, separation of soil and substrate, and transport of dislodges soil into the wash bath. The quantification of the mass of the residual oil is well defined using the radioisotope methodology. The effectiveness of lipase on removal of lard stains is observed at all points in the washing cycle (5, 10, 20, 60 min). After a 60-min wash with detergent plus lipase, 68.5% of the lard was removed. Our data fit a classical kinetic description of the soil removal process described by an exponential decay, with the presence of lipase greatly increasing the rate of oil removal during the early period of washing (0 to 20 min). With the use of lipase in the washing bath, the amount of soil removal after 10 min is about the same as observed after washing 60 min with deteregent only. Hydrolysis of triglycerides forms mono- and diglycerides and fatty acids. These hydrolysis products are more soluble in water, can undergo soap formation, enhance mesomorphic phase formation, and increase emulsification.

Impacts
(N/A)

Publications

Chi, Yong-Seung and Obendorf, S.K. 1998. Preventing Discoloration of Squalene-Soiled Cotton Fabrics with Antioxidants, Journal of Surfactants and Detergents 1:519-522.
Chi, Yong-Seung and Obendorf, S.K. 1998. Aging of Oily Soils on Textile Materials: A Literature Review, Journal of Surfactants and Detergents 1:407-418.
Chi, Yong-Seung and Obendorf, S.K. 1998. Aging of Oily Soils on Textile Materials: Chemical Changes upon Oxidation and Interaction of Aged Oils with Textile Fibers, Journal of Surfactants and Detergents 1:371-380.
Choe, E-K. and Obendorf, S.K. 1998. Neutron Activation Analysis as a Method for Measuring Soil Removal of Unsaturated Oils and for Estimating The Degree of Aging on Fabric, Journal of Surfactants and Detergents 1:227-233.

Progress 01/01/97 to 12/31/97

Outputs
The aging of unsaturated oily soils on textile materials produces yellow compounds that are difficult to remove by washing. To investigate the changes that occur in oily soils when aged, the aging of squalene and artificial sebum were studied. 1H-NMR, IR spectroscopy, GC and GPC studies showed that the oily soils were oxidized upon aging, forming low molecular weight products that also polymerized into higher molecular weight compounds with prolonged aging. The oxidation products carried hydroxyl, carbonyl or ester groups. Oxidation compounds carrying yellow chromophores appeared to be mostly those of the 1000 2500 molecular weight fraction; though in earlier stages of aging, lower molecular weight fractions also contained chromophores. By using glucose as a model compound of cellulose, it was found that yellow oxidation products of aged squalene covalently bond to the substrate. As the aging of oily soils is a free-radical oxidation process, oxidation products carrying chromophores are thought to attach to the cotton substrate through radical coupling. Oily soils also showed possibilities of chemical bonding with nylon but not with polyester.

Impacts
(N/A)

Publications

CHI, Y-S. 1997. Chemical Changes in Oily Soils upon Aging and Their Interaction with Textile Fibers, Ph.D. Dissertation. Cornell
LEE, J-S. and OBENDORF S.K. 1997. The Application of Rutherford Backscattering Spectrometry for Analyzing the Removal of Oily Soil by Detergency, Symposium on Detergency, Japanese Oil Chemistry Society,
CHOE, E-K. and OBENDORF, S.K., 1998. Neutron Activation Analysis as a Method for Measuring Soil Removal of Unsaturated Oils and for Estimating Their Degree of Aging on Fabric, Journal of Surfactants
CHI, Y-S. and OBENDORF, S.K. 1998. Aging of Oily Soils on Textile Materials: Part I Literature Review, Journal of Surfactants and
CHI, Y-S. and OBENDORF, S.K. 1998. Aging of Oily Soils on Textile Materials: Part II Chemical Changes upon Oxidation and Interaction of Aged Oils with Textile Fibers, Journal of Surfactants and Detergents

Progress 01/01/96 to 12/30/96

Outputs
Current environmental concerns have prompted a need to reduce fats, oils, and greases (FOGs) in industrial laundry effluent. The current work uses a radioisotope tracer protocol to evaluate the laundry performance and demulsification ability of destructible surfactants as a potential alternative to reversible surfactants for decreasing FOGs in industrial laundry effluent prior to elimination from the plant. Both reversible and destructible surfactants demulsify much more oil from wash water waste than the industrial standard Tergitol# NP-9, with similar laundry performance. A kinetic analysis of the rate of demulsification for the destructible surfactants confirms the different demulsification mechanism from the reversible surfactant and the industrial standard. Destructible surfactants perform as well as reversible surfactants with respect to laundry performance and demulsification ability and are able to remove up to 80% of the wash water contamination within a few hours.

Impacts
(N/A)

Publications

OBENDORF, S. K., LADUCA, M.J., RAVICHANDRAN, V., JOSEPH, A. F., GALANTE, D., andSTEFL, B.
A., Reduction of Fats, Oils and Greases in Effluent from Industrial Laundry, Journal of American Oil Chemists Society, (in preparation).

Progress 01/01/95 to 12/30/95

Outputs
Current environmental concerns have prompted a need to reduce fats, oils, and greases (FOGs) in industrial laundry effluent. The current work uses a radioisotope tracer protocol to evaluate the laundry performance and demulsification ability of destructible surfactants as a potential alternative to reversible surfactants for decreasing FOGs in industrial laundry effluent prior to elimination from the plant. Both reversible and destructible surfactants demulsify much more oil from wash water waste than the industrial standard Tergitol NP-9, with similar laundry performance. A kinetic analysis of the rate of demulsification for the destructible surfactants confirms the different demulsification mechanism from the reversible surfactant and the industrial standard. Destructible surfactants perform as well as reversible surfactants with respect to laundry performance and demulsification ability and are able to remove up to 80% of the wash water contamination within a few hours.

Impacts
(N/A)

Publications

Progress 01/01/94 to 12/30/94

Outputs
Efforts continue to develop methodology for the evaluation of reversible surfactants. An improved kinetic sampling procedure was developed and a possible kinetic model was proposed. When using radioisotope labeling to evaluate the residual oil on fabrics extraction of the oil from the fabric can occur within the scintillation vial providing several days of extraction time is used. As an example of the results that can be obtained using the protocol for kinetic studies, the Triton RW-75 reversible surfactant (an alkyl amine ethoxylate) removed all but 11% of the soil initially deposited on cotton fabric when laundered at a pH of 11.0. Of the 89% of the soil present in the wash water, this surfactant separated 50% upon acidification, creating a scum layer above the emulsion. The half life of this demulsification process for Triton RW-75 was 2.1 hours.

Impacts
(N/A)

Publications

PARK, E-K. C. AND OBENDORF, S. K. 1994. Chemical Changes in Unsaturated Oils upon Aging and Subsequent Effects on Soil Removal and Fabric Appearance, Journal of American Oil Chemists' Society. 71: 17-30.

Progress 01/01/93 to 12/30/93

Outputs
An experimental protocol has been developed to evaluate the performance of surfactant in oily soil removal during laundry, coupled with their propensity to demulsify upon acidification of the wash water. The surfactants first tested were a nonyl phenol ethoxylate (NP-9) and an alkyl amine ethoxylate (RW-75). The oily soil was used motor oil spiked with tritium labeled triolein. Oily soil removal by the surfactant and the subsequent demulsification potential under varying temperature conditions were measured by liquid scintillation counting. Oily soil removal of NP-9 was higher than that for RW-75. However, RW-75 vastly out performed NP-9, with regards to acid-induced demulsification and subsequent separation of the oil and water phases. This protocol was modified to use labeled squalene as the tagged oil, and more heavily soiled fabric was used to more accurately model an industrial laundry setting. A series of glyceryl ethoxylates were evaluated for performance as reversible surfactants. The technique was also used to monitor the demulsification of wash water over a period of three hours, both with and without acidification. Acidification of the wash water increased the demulsification over this time period.

Impacts
(N/A)

Publications

PARK, E-K. C. AND OBENDORF, S.K. 1994. Chemical Changes in Unsaturated Oils upon Aging and Subsequent Effects on Soil Removal and Fabric Appearance, Journal of American Oil Chemists' Society. (in press).